} // End Class DbDnsRecord static async Task <bool> ResolveMessage(DnsMessage query, QueryReceivedEventArgs e, DnsMessage response) { DbDnsRecord rec = null; using (System.Data.Common.DbCommand cmd = s_sql.CreateCommand(@" -- DECLARE @in_recordType int -- DECLARE @in_recordName varchar(4000) -- SET @in_recordType = 1 -- A -- SET @in_recordName = 'vortex.data.microsoft.com' SELECT REC_Id --,T_Records.REC_DOM_Id ,T_Records.REC_RT_Id ,T_Records.REC_Name ,T_Records.REC_Content ,T_Records.REC_ResponsibleName ,COALESCE(T_Records.REC_TTL, 100) AS REC_TTL ,T_Records.REC_Prio ,T_Records.REC_Weight ,T_Records.REC_Port ,T_Records.REC_SerialNumber ,T_Records.REC_RefreshInterval ,T_Records.REC_RetryInterval ,T_Records.REC_ExpireInterval ,T_Records.REC_NegativeCachingTTL ,T_Records.REC_AfsSubType ,T_Records.REC_ChangeDate FROM T_Records WHERE REC_RT_Id = @in_recordType AND T_Records.REC_Name = @in_recordName ; ")) { try { string name = query.Questions[0].Name.ToString(); s_sql.AddParameter(cmd, "in_recordType", (int)query.Questions[0].RecordType); s_sql.AddParameter(cmd, "in_recordName", name); // TODO: Can return multiple records... rec = s_sql.GetClass <DbDnsRecord>(cmd); } catch (System.Exception ex) { System.Console.WriteLine(ex.Message); System.Console.WriteLine(ex.StackTrace); } } // End Using cmd if (rec != null) { int ttl = 3600; DnsRecordBase record = null; // https://blog.dnsimple.com/2015/04/common-dns-records/ // https://en.wikipedia.org/wiki/List_of_DNS_record_types switch ((RecordType)rec.REC_RT_Id) { case RecordType.Soa: // SoaRecord(DomainName name, int timeToLive, DomainName masterName // , DomainName responsibleName, uint serialNumber, int refreshInterval // , int retryInterval, int expireInterval, int negativeCachingTTL) record = new ARSoft.Tools.Net.Dns.SoaRecord( DomainName.Parse(rec.REC_Name) , rec.REC_TTL.Value , DomainName.Parse(rec.REC_Content) , DomainName.Parse(rec.REC_ResponsibleName) , rec.REC_SerialNumber.Value , rec.REC_RefreshInterval.Value , rec.REC_RetryInterval.Value , rec.REC_ExpireInterval.Value , rec.REC_NegativeCachingTTL.Value ); break; case RecordType.Ns: record = new ARSoft.Tools.Net.Dns.NsRecord(DomainName.Parse(rec.REC_Name), ttl, DomainName.Parse(rec.REC_Content)); break; case RecordType.Srv: // SrvRecord(DomainName name, int timeToLive, ushort priority, ushort weight, ushort port, DomainName target) record = new ARSoft.Tools.Net.Dns.SrvRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, (ushort)rec.REC_Prio.Value, (ushort)rec.REC_Weight.Value, (ushort)rec.REC_Port.Value, DomainName.Parse(rec.REC_Content)); break; // https://www.openafs.org/ // https://en.wikipedia.org/wiki/OpenAFS // http://www.rjsystems.nl/en/2100-dns-discovery-openafs.php // OpenAFS is an open source implementation of the Andrew distributed file system(AFS). case RecordType.Afsdb: // http://www.rjsystems.nl/en/2100-dns-discovery-openafs.php record = new ARSoft.Tools.Net.Dns.AfsdbRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, (AfsdbRecord.AfsSubType)(uint) rec.REC_AfsSubType.Value, DomainName.Parse(rec.REC_Content)); break; // A DNS-based Authentication of Named Entities (DANE) method // for publishing and locating OpenPGP public keys in DNS // for a specific email address using an OPENPGPKEY DNS resource record. case RecordType.OpenPGPKey: byte[] publicKey = null; // hexdump(sha256(truncate(utf8(ocalpart), 28) // https://www.huque.com/bin/openpgpkey // The OPENPGPKEY DNS record is specied in RFC 7929. // The localpart of the uid is encoded as a DNS label // containing the hexdump of the SHA-256 hash // of the utf-8 encoded localpart, truncated to 28 octets. // Normally the "Standard" output format should be used. // The "Generic Encoding" output format is provided to help work // with older DNS software that does not yet understand the OPENPGPKEY record type. record = new ARSoft.Tools.Net.Dns.OpenPGPKeyRecord(DomainName.Parse(rec.REC_Name), ttl, publicKey); break; // Canonical name records, or CNAME records, are often called alias records because they map an alias to the canonical name. When a name server finds a CNAME record, it replaces the name with the canonical name and looks up the new name. case RecordType.CName: record = new ARSoft.Tools.Net.Dns.CNameRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, DomainName.Parse(rec.REC_Content)); break; case RecordType.Ptr: record = new ARSoft.Tools.Net.Dns.PtrRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, DomainName.Parse(rec.REC_Content)); break; case RecordType.A: record = new ARSoft.Tools.Net.Dns.ARecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, System.Net.IPAddress.Parse(rec.REC_Content)); break; case RecordType.Aaaa: record = new ARSoft.Tools.Net.Dns.AaaaRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, System.Net.IPAddress.Parse(rec.REC_Content)); break; case RecordType.Mx: record = new ARSoft.Tools.Net.Dns.MxRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, 0, DomainName.Parse(rec.REC_Content)); break; case RecordType.Txt: record = new ARSoft.Tools.Net.Dns.TxtRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, rec.REC_Content); break; case RecordType.SshFp: // https://unix.stackexchange.com/questions/121880/how-do-i-generate-sshfp-records // SshFpRecord(DomainName name, int timeToLive, SshFpAlgorithm algorithm // , SshFpFingerPrintType fingerPrintType, byte[] fingerPrint) ARSoft.Tools.Net.Dns.SshFpRecord.SshFpAlgorithm sfa = ARSoft.Tools.Net.Dns.SshFpRecord .SshFpAlgorithm.Rsa; ARSoft.Tools.Net.Dns.SshFpRecord.SshFpFingerPrintType sfp = ARSoft.Tools.Net.Dns.SshFpRecord .SshFpFingerPrintType.Sha256; byte[] fp = null; record = new ARSoft.Tools.Net.Dns.SshFpRecord(DomainName.Parse(rec.REC_Name), rec.REC_TTL.Value, sfa, sfp, fp); break; default: break; } // End Switch if (record != null) { response.AnswerRecords.Add(record); } response.ReturnCode = ReturnCode.NoError; e.Response = response; return(await Task <bool> .FromResult(true)); } // End if (rec != null) return(await Task <bool> .FromResult(false)); } // End Function ResolveMessage
private static void OnQueryReceived(object sender, QueryReceivedEventArgs e) { StringBuilder sb = new StringBuilder(); try { DnsMessage message = e.Query as DnsMessage; message.IsQuery = false; if (message == null || message.Questions.Count == 0) { e.Response = message; message.ReturnCode = ReturnCode.ServerFailure; e.Response = message; Console.WriteLine(sb); return; } //Log DNS query sb.AppendFormat("* {0}\r\n", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff")); for (int i = 0; i < message.Questions.Count; i++) { sb.AppendFormat("[{0}]\t{1}\t{2}\r\n", i, message.Questions[i].RecordType.ToString(), message.Questions[i].Name); } if (message.Questions.Count > 1) { sb.AppendFormat("Response: (x) ServerFailure -- Multiple questions\r\n"); e.Response = message; message.ReturnCode = ReturnCode.ServerFailure; e.Response = message; Console.WriteLine(sb); return; } DnsQuestion question = message.Questions[0]; if (!question.Name.Equals(domain, StringComparison.CurrentCultureIgnoreCase) && !question.Name.EndsWith(string.Concat(".", domain), StringComparison.CurrentCultureIgnoreCase)) { e.Response = message; message.ReturnCode = ReturnCode.ServerFailure; e.Response = message; sb.AppendFormat("Response: (x) ServerFailure -- Domain \"{0}\" is invalid\r\n", question.Name); Console.WriteLine(sb); return; } if (question.RecordType == RecordType.Txt) { //MX message.ReturnCode = ReturnCode.NoError; message.AnswerRecords.Add(new TxtRecord(domain, ttlSeconds, "Hello world")); message.ReturnCode = ReturnCode.NoError; e.Response = message; sb.AppendFormat("Response: OK!\r\n", question.Name); Console.WriteLine(sb); return; } else if (question.RecordType == RecordType.A) { //A string subdomain = question.Name.Substring(0, question.Name.LastIndexOf(domain)); if (subdomain.Length > 0) subdomain = subdomain.Substring(0, subdomain.Length - 1); //remove o ponto if (subdomain.Length == 0) { //raiz do domínio var record = new ARecord(question.Name, ttlSeconds, System.Net.IPAddress.Parse("192.168.1.1")); message.AnswerRecords.Add(record); message.ReturnCode = ReturnCode.NoError; e.Response = message; sb.AppendFormat("Response: OK!\r\n", question.Name); return; } else { //subdomínios if (subdomain.Length > 0 && subdomain.StartsWith("local_", StringComparison.CurrentCultureIgnoreCase)) { //recebe: local_192-168-10-10.[domain] e retorna: "192.168.10.10" string ipString = subdomain.Substring("local_".Length); ipString = ipString.Replace("-", "."); System.Net.IPAddress ipAddress; if (System.Net.IPAddress.TryParse(ipString, out ipAddress)) { var record = new ARecord(question.Name, ttlSeconds, ipAddress); message.AnswerRecords.Add(record); message.ReturnCode = ReturnCode.NoError; e.Response = message; sb.AppendFormat("Response: OK!\r\n", question.Name); Console.WriteLine(sb); return; } else { sb.AppendFormat("Response: (x) ServerFailure -- Invalid IP \"{0}\" invalid. Example of subdomain valid: \"local_192-168-10-10\"\r\n", ipString); message.ReturnCode = ReturnCode.ServerFailure; e.Response = message; Console.WriteLine(sb); return; } } else { sb.AppendFormat("Response: (x) ServerFailure -- Subdomain \"{0}\" invalid. Example of subdomain valid: \"local_192-168-10-10\"\r\n", subdomain); message.ReturnCode = ReturnCode.ServerFailure; e.Response = message; Console.WriteLine(sb); return; } } } sb.AppendFormat("Response: (x) ServerFailure -- Record Type \"{0}\" invalid\r\n", question.RecordType.ToString()); message.ReturnCode = ReturnCode.ServerFailure; e.Response = message; } catch (System.Exception ex) { sb.AppendFormat("{0} EXCEPTION: {1}\r\n{2}\r\n\r\n", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff"), ex.Message, ex.StackTrace); } Console.WriteLine(sb.ToString()); }